Vaccine technology: looking to the future

The impact of vaccination on the health of the world's peoples has been con siderable. With the possible exception of clean water, no other development has had such a major effect on the reduction of mortality and on populatio n growth. During the last 200 years, vaccination has controlled nine major diseases and has led to the eradication of one, ie smallpox. However, in ma ny instances the exact mechanisms of successful vaccines are not fully unde rstood. Almost all of the vaccines in use today are of three types: live at tenuated micro-organisms, inactivated whole micro-organisms, or split or su bunit preparations. These have different strengths and weaknesses with resp ect to safety and efficacy, but traditional vaccine development methodologi es have not yet led to the generation of a vaccine with all the characteris tics required of the ideal vaccine. Thus, the development of improved vacci nes that overcome the difficulties associated with many of the currently av ailable vaccines is a major goal of biomedical sciences. In addition, there is an urgent need for new vaccines against the many infectious agents that still cause considerable morbidity and, in some cases, mortality. As has b een the case in many areas of biology, the application of recombinant DNA a pproaches to vaccinology has opened up whole new possibilities. The details of these and other technologies and their application to vaccine developme nt are described in this review.